Hydroxyproline, a non-essential amino acid derived from proline, with no known therapeutic use. Hydroxproline is used as a major component of structural protiens such as collagen, connective tissues, plant cell walls, tendons and ligaments and provides skin elasticity. Vitiman C is required for the conversion process from proline to hydroxyproline, a deficincy in vitiman C can lead to defects in collagen synthesis, thus, resulting in easy bruising, internal bleeding, breakdown of connective tissue of the ligaments and tendons, and increased risk to blood vessel damage. An unusual feature of this amino acid is that, it is not incorporated into collagen during biosynthesis at the ribosomal level, but is formed from proline by a posttranslational modification by an enzymatic hydroxylation reaction.